scsi-disk: change disk serial length from 20 to 36

Openstack Cinder assigns volume a 36 characters uuid as serial.
QEMU will shrinks the uuid to 20 characters, which does not match
the original uuid.

Note that there is no limit to the length of the serial number in
the SCSI spec.  20 was copy-pasted from virtio-blk which in turn was
copy-pasted from ATA; 36 is even more arbitrary.  However, bumping it
up too much might cause issues (e.g. 252 seems to make sense because
then the maximum amount of returned data is 256; but who knows there's
no off-by-one somewhere for such a nicely rounded number).

Signed-off-by: Rony Weng <ronyweng@synology.com>
Message-Id: <1472457138-23386-1-git-send-email-ronyweng@synology.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 48b6206305b8d56524ac2ee347b68e6e0a528559)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 836a1553edd0b8f00a7b8fefb3f5f67b6d83dd42..0e1bb6814abb2d11632d5588befc71b989b4726e 100644 (file)
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -599,8 +599,8 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
             }
 
             l = strlen(s->serial);
-            if (l > 20) {
-                l = 20;
+            if (l > 36) {
+                l = 36;
             }
 
             DPRINTF("Inquiry EVPD[Serial number] "